Clutch-head torque indicating wrench



Nov. 14, 1950 R. A. JOHNSON CLUTCH-HEAD TORQUE INDICATING WRENCH Filed Nov. 22, 1946 1/1 z'culor Rickard QJk nsari/ O B w m M. W I I l p E I ittarne Patented Nov. 14, 1950 CLUTCH-HEAD TORQUE INDICATING WRENCH Richard A. Johnson, West Union, Iowa Application November 22, 1946, Serial No. 711,774

8 Claims.

This invention relates to certain new and useful improvements in socket Wrenches of a ratcheting clutch-head type in which a rigid, annular head or annulus on the outer end of an ordinary handle encompasses and substantially embraces a centrally socketed head and wherein the latter is fashioned to carry coacting spring-pressed, friction clutch rollers; but has reference in particular to special means which is employed in association with said heads and is adapted to measure and indicate the turning effort or torque required to properly and safely use the wrench in a manner to prevent over-tightening and undertightening of bolts and nuts, and to thus save against distortion of screw-threads.

More specifically, the invention centers in and is founded upon a carefully perfected instrumentality embodied in workably related, precision balanced mechanical parts characterized, as above mentioned, and including a simple and expedient addition to a somewhat conventionally constructed wrench; said instrumentality functioning to pick up and translate the relative angular movements of said annulus and head to visibl translate the axial rotary movements of said head to an index on the handle, whereby to suitably measure the degree of twisting force required to drive a nut or bolt home, this measurement in relation to the longitudinal axis of said handle.

Briefly and broadl recited, and viewed from a structural standpoint, the disclosure herein embodied has to do with a socket wrenchof a clutch-head type comprising an elongated handle having a fixed annular head at one end, a centrally socketed clutch-head confined and mounted for rotation in said annular head and including suitable friction clutch means, and torque indicating and measuring means coasting with the clutch-head and handle to assist a user in ascertaining and determining excessive stresses and strains in a manner to prevent over-tightening of bolts and nuts and to minimize the likelihood of stripping and distorting screw-threads or breakage of the wrench.

Another phase and object of the invention has to 'do with a friction-type clutch-head wrench for manual use in which the handle, annular head, clutch-head, friction grips and assembling and retaining washers are somewhat old and well known, from a general point of view, the invention itself being extremely simple in that it is characterized by a ring-like member with detents pressed into frictional contact with a clutchhead, said ring-like member being provided with an outstanding tang like extension functioning as an indicator finger, the same having a scale for coaction with an index fixedly mounted on a simple plate carried by a wrench handle.

The general object of the invention is to structurally, functionally and otherwise improve upon wrenches in the category under advisement, this by providing simple, reliable, and practical means 1 whereby it is convenient and possible to measure the degree of twist or torque required and the amount of applied handle-turning force in relation to the load moved, this to attain the ends previousl set forth.

Other objects, features and advantages will become more readily apparent from the following description and the accompanying illustrative drawings.

In the drawings, wherein like numerals are Figure 4 is a perspective view of the clutch-V head per se.

Figure 5 is a perspective View of the principle part of the invention, the clutch-head motion pickup, translating and indicator unit.

Figure 6 is a section on the line 6-6 of Figure 5, looking in the direction of the arrows.

Referring now'to the drawings by distinguish- .ing reference numerals, it will be seen that the handle means is broadly denoted at A, the clutch.- head, or headed-clutch, as it is sometimes re-.

ferred to in the art, is indicated atB and that. the principal part orunit forming the major feature in the;.measuring instrumentality is indicated at-C (see Figs; 5 and 6).

The handle means A comprises a suitable handle 8 with a fixed annular head 9 at its outer.- end. The head on-one side, which we may conveniently call the bottom, is formed with a re-. cess 9a in which an-assembling washer or plate ll! is seated, asshown in Figure 3. Fitted into J the surrounding annulus or annular head-9v is the clutch-head; B, ythiSf being in the form 'of a body (see -Fig. 4) having-a central tool and worki socket I l and being provided with marginal, equh distant, circumferentially spaced notches or pockets l2 to accommodate friction clutch rollers l3 pressed against the inner periphery of the annular head 9 by way of coiled springs [4. Also confined within the limits of the annular head 9 is another assembling washer l5 (see Fig. 3) and outwardly of this is a third cover-forming and facing washer I6, said several washers being bolted in place by bolts l1 and said bolts serving,

to thus group and assemble all of the parts which go to make up the clutch-head unit or assembly. The measuring unit C, comprises an annulus;

or ring l8 of metal or the like, the same having I9 at circumferentially spaced.

indentations points, said indentations forming springy detents and bearing frictionally against-the adjacent outer surface of the washer l5, as shown in Figure 3. The annulus I8 is provided with a tang-like By way of introduction to the, mode of operation of my wrench, it will perhaps simplify matters if the reader visualizes the scale-carrying torque measuring and indicating meansC and clutch-head B as one unit or assembly. However, it is to be remembered that even though means C is bolted and thus frictionally clamped (between l5 and IE) to head B, it nevertheless has limited relative rotary movement to head B. Secondly, the handle 8 plusits annulus 9 and fixed index 24 (part A) may 'be visualized as a second unit, complemental to said first-named unit.

Now, let us take up the first stage or cycle of operation and assume, in so doing; that the work (nut, bolt, socket, tool or-the like) is loose and therefore freely turnable. So, We place the socket l I of head B on the work (not shown) and, with the roller clutch l2 and-l3 means positively locking the annulus 9 to the head B, swing handle 8 clockwise. Visualizing this step,- it will be seen that the work, head B, indicator -means C and handle means A travel together, that is, in unison. On the return swing or stroke, the head B stays put with the work and the handle means A picks up and swings the indicator means C back to the starting position for a new hold. This action is .due to the fact that the stop screw'zz is in abutting contact with the right hand end of slot 2| (see Fig. 1), and also because of the return slip action of the ring l8 -between washerslS and 16. Consequently, the means C is responsive to and moves in a clockwise direction with the clutch-head B and handle means A; and is,

alsoiresponsive and moves in a counter-clockwise direction in unison with handleunit or means A, while the clutch head B stays put. Thus, we complete one cycle of the operation and, obvious- 1y, said cycle is repeated until the work, initially loose and turnable, is now substantially home 4 ening resistance of said work and when further pressure is brought to bear on said handle 8, the clutch rollers l3 ride to final wedging and locking positions in pockets I2. This is the stage when the torque measuring and indicating means becomes significant and comes into play and begins to register, thus to give the desired pounds pressure reading on scale 23. At this stage, finger 20 is now stationary with clutch-head B, and handle 8, together with plate 25 and index 24, continues to move (as the rollers l3 ram and jam into shallow ends of said pockets l2) clockwise, resulting in movement of said index 24 along scale 23 and revealing the desired measurement in stated pounds pressure. As is evident, when index 24 swings across the then stationary scale, the stop screw 22 also rides from right to left in slot 2|. The given measurement is noted and mentally retained, and the cycle is repeated, which results in the index 24 moving back to zero for the next new hold and take-up 'step, provided a further measurement has to be taken.

From the foregoing, it is evident that means C is not actuated in response to all movement of the clutch-head B and the surrounding annular head 9 but only to the apparently slight movement permitted by the rollers 13 whenthe handle S is moved in a clockwise direction tending to lock the clutch-head B to the surrounding annular head 9.

The workability and inter-relationship of the parts described results in a sensitive, precisiontype ratchet Wrench, through the medium of which it is possible to measure the degree of, twist, or twisting force which has to be applied to a handle in order to turn the load.

an'ove'r-strain and thus prevent (1) breakage of the wrench and (2) distortingof coacting threads, between a nut and bolt or equivalent assembly.

In view of the foreging descriptiontaken. in conjunction with the'accompanying drawings, it is believed that a clear understanding of .the construction, operation and advantages of the.

" device will be quite apparent to those skilled'in A more detailed description is accordthis art. ingly deemed unnecessary.

.It is to be understood, however, that even though I have herein shown and described, a I preferred embodiment of my invention that the opposite sides of and fastened to said head, a. third washer spaced from .the top washer and also,

fastened to said head, a ring-like member inter:

posed movably between the third-namedandtop...

washers and includingdetents frictionally contacting said top washer and further includingan...

extension forming an indicating finger, the'latterbeing. parallel to and movable withas well-as in relation to said handle.

2. A socket wrench of the clutch head type,

comprising a handle having a fixed annular head,'.. a centrally socketed clutch-head confinedand mounted for rotation in saidannular head; an.,.. assembling and retaining washer. mounted ,withgj 1?;

It follows that the user is thus provided with a simple and expedient means enabling him to promptly detect in the confines of said annular head and being in contact with said clutch-head, a second washer mounted within the confines of said annular head and resting against the opposite face of said clutch-head, a third washer, bolts securing said several washers and clutch-head together in assembled turnable relationship, a ring-like member interposed between the second and third washers and having circumferential bends forming friction detents coacting with the secondnamed washer, said ring-like member being provided with an extension forming an indicating finger.

3. A socket wrench of the clutch-head type comprising a handle having a fixed annular head at its outer end, a centrally socketed clutch-head confined and mounted for operational rotation in said annular head, an assembling and retaining washer mounted within the confines of said annular head and in contact with one face of said clutch-head, a second Washer mounted within the confines of said annular head and resting against the opposite face of said clutch-head, a third washer, bolts securing said several washers and clutch together in assembled simultaneously turnable relationship, a ring-like member interposed for relative rotary movement between the second and third washers and having circumferential bends forming friction detents coacting with the second-named washer, said ring-like member being provided with an extension forming an indicating finger, said indicating finger having a graduated scale, and said handle having a fixed index coactable with said scale.

4. A socket Wrench of the clutch-head type comprising a handle having a fixed annular head at its outer end, a socketed clutch-head confined and mounted for rotation in said annular head, an assembling and retaining washer mounted for rotation within the confines of said annular head and being in contact with said clutch-head, a second washer mounted within the confines of said annular head and resting against the opposite face of said clutch-head, a third washer, bolts securing said several washers and head together in assembled turnable relationship, a ring-like member interposed between the second and third Washers and having circumferential bends forming friction detents coacting with the secondnamed washer, said ring-like member being provided with an extension forming an indicating finger, said indicating finger being slotted, said handle being provided with a stop screw and said stop screw being operable in said slot.

5. A socket wrench of the clutch-head type comprising an elongated handle having a fixed annular head at its outer end, a centrally socketed clutch-head confined and mounted for rotation in said annular head, an assembling and retaining washer mounted within the confines of said annular head and being in contact with said clutch-head, a second washer mounted within the confines of said annular head and resting against the opposite face of said clutch-head, a third washer, bolts securing said several washers and head together in unitarily assembled turnable relationship, a ring-like member interposed between the second and third washers and having circumferential bends forming friction detents coacting with the second-named washer, said ring-like member being provided with an extension forming an indicating finger, said indicating finger being slotted, said handle being provided with a stop screw and said stop screw being operable in said slot, and said finger being provided with a measuring scale, and said handle being provided with a fixed index with which the graduations of the measuring scale coact.

6. A ratcheting type clutch-head socket Wrench of the class shown and described comprising a handle provided with an annular head and further provided at a predetermined point with an index fixed on said head, a work-engaging and turning head mounted for rotation in said annular head, friction clutch means interposed between coacting marginal portions of said heads, a force indicating unit having a portion opposed to said turning head and an indicating finger opposed and parallel to said handle and having a scale with which said index is cooperable, and means for frictionally assembling and clamping said portion against said turning head and permitting said indicating unit to move with as well as relative to said turning head.

7. The structure specified in claim 6 wherein said indicating finger is provided at its outer swingable end with a transverse arcuate slot, and a stop screw is carried by said handle and projects into and through said slot.

8. A ratcheting type dual headed wrench of the class shown and described comprising an annular head provided with a rigid handle, a second head fitted within the confines of said annular head and provided with a work-engaging socket, ratcheting means interposed between peripheral portions of said heads, a ring-like member opposed to one face of said second-named head and having an indicating finger opposed and parallel to said handle, said indicating finger being provided with a transverse arcuate slot and a graduated measuring scale cooperable with the slot, a stop screw mounted in said handle and fitting into said slot, said handle having a relatively fixed index and said index being registrable with the graduations on said scale, a clamping and assembling member connected with said second-named head, said ring member being interposed between the clamping member and said second-named head and movable in conjunction with as well as separately from said last-named head.

RICHARD A. JOHNSON.

REFERENCES CITED The following references are of record in the 

